hashicorp/nomad · error

http_max_size not a valid size: %w

Error message

http_max_size not a valid size: %w

What it means

This error is returned by ArtifactConfig.Validate in nomad/structs/config/artifact.go when the http_max_size string cannot be parsed as a byte size (e.g. "10gb", "500MB") by the humanize.ParseBytes parser. Nomad validates client artifact block configuration at load time so malformed agent configs fail fast. The wrapped parse error (%w) tells you exactly which part of the string the parser rejected.

Source

Thrown at nomad/structs/config/artifact.go:179

func (a *ArtifactConfig) Validate() error {
	if a == nil {
		return fmt.Errorf("artifact must not be nil")
	}

	if a.HTTPReadTimeout == nil {
		return fmt.Errorf("http_read_timeout must be set")
	}
	if v, err := time.ParseDuration(*a.HTTPReadTimeout); err != nil {
		return fmt.Errorf("http_read_timeout not a valid duration: %w", err)
	} else if v < 0 {
		return fmt.Errorf("http_read_timeout must be > 0")
	}

	if a.HTTPMaxSize == nil {
		return fmt.Errorf("http_max_size must be set")
	}
	if v, err := humanize.ParseBytes(*a.HTTPMaxSize); err != nil {
		return fmt.Errorf("http_max_size not a valid size: %w", err)
	} else if v > math.MaxInt64 {
		return fmt.Errorf("http_max_size must be < %d but found %d", int64(math.MaxInt64), v)
	}

	if a.GCSTimeout == nil {
		return fmt.Errorf("gcs_timeout must be set")
	}
	if v, err := time.ParseDuration(*a.GCSTimeout); err != nil {
		return fmt.Errorf("gcs_timeout not a valid duration: %w", err)
	} else if v < 0 {
		return fmt.Errorf("gcs_timeout must be > 0")
	}

	if a.GitTimeout == nil {
		return fmt.Errorf("git_timeout must be set")
	}
	if v, err := time.ParseDuration(*a.GitTimeout); err != nil {
		return fmt.Errorf("git_timeout not a valid duration: %w", err)

View on GitHub (pinned to 482b49bf1a)

Solutions

1. Fix the http_max_size string to a value humanize.ParseBytes accepts, e.g. "1gb", "500MB", "1024kb" (decimal SI units, no commas or spaces).
2. Use a bare byte count like "1073741824" if no unit is desired.
3. Check the wrapped %w error text to identify the exact offending character(s).
4. Re-run nomad agent -config validation (or `nomad validate`) before restarting the agent.

Example fix

// before
artifact {
  http_max_size = "1,000MB"
}
// after
artifact {
  http_max_size = "1000MB"
}

// Go: check before building/submitting config
func validHTTPMaxSize(s *string) bool {
    if s == nil { return false }
    _, err := github.com/dustin/go-humanize.ParseBytes(*s) // humanize.ParseBytes
    return err == nil
}
// Acceptable: "1gb", "500MB", "1073741824". Reject commas, spaces, unknown units.

func isByteSize(s string) bool {
    _, err := humanize.ParseBytes(s)
    return err == nil
}

When it happens

Trigger: Setting `http_max_size` in an artifact config block to a string that humanize.ParseBytes cannot parse: non-numeric text ("ten gb"), unsupported units ("10kibibytes" misspelled, "10b/s"), a bare number with a trailing character ("10GB " with space or "10,Gb"), or an empty string.

Common situations: Copy-pasting config from docs with smart quotes or stray whitespace; assuming a bare integer or a unit humanize does not recognize works; typos like "10GBs" or "1,000MB"; templating tools injecting an empty or malformed value; upgrading Nomad after http_max_size was introduced and mixing old config fragments.

Understand the failure class

Background: "Invalid value" and "allowed values are" config errors: what your library rejected and how to fix it — this error's family across 41 libraries.

Related errors

• wait config is nil or empty
• missing datacenter for client registration
• default_identity_ttl must be greater than 0
• max_identity_ttl must be greater than 0
• max_identity_ttl must be greater than or equal to default_id

AI-assisted analysis of hashicorp/nomad@482b49bf1a (2026-09-04). Data as JSON: /api/errors/aec3c5d3442e0bc6. Report an issue: GitHub.